Artificial stone



(No Model.)

D. Gr. WBEMS.

ARTIFICIAL STONE. No. 274,237. Patented Ma.1'.20, 1883.

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N. PHERS. Mmmm. WxiNnliull. D. C-

UNITED STATES PATENT OEETCE.'

DAVID G. WEEMS, OF BALTIMORE, MARYLAND.

ARTIFICIAL SToNE.

SPECIFICATION forming part of Letters Patent No. 274,237, dated March 20, 1883.

To all whom t may concern:

Application tiled VOctober 10, 1881. (No model.)

by passing the gas under and through a body Be it known that I, DAVID G. WEEMS, of of water it can be thoroughly cleansed of all Baltimore city, State ot' Maryland, have invented certain new and useful Improvements in the Manufacture of Artificial Stone; and I hereby declare the same to be fully, clearly, and exactly described as follows:

My invention has reference to the manufacture ot' artificial stone, into which enters as an ingredient any 011e or more of the standard and well-known calcareous cements; and it has for its object to render the stone harder and more durable than has heretofore been possible, following the usual and well-known methods. Y,

It has long been known that slabs, tiles, pipes, or otherarticles formed, in whole or in part, of mixtures of sand and cementare rendered, in a short time, if subjected to the action otl carbonio-acid gas, as hard as they would I otherwise become only after the lapse of considerable time. It has been generally customary to place the articles, while fresh from the molds and still damp, in a chamber into which were conducted the products of combustion from a suitable furnace. The gases so produced are quite hot as they enter the cham ber, and are anything but pure, being a mixture of carbonio acid, carbonio oxide, water-vapor, and nitrogen, besides containing all the natural impurities of the air and fuel-such as traces of sulphureted hydrogen and sulphurous`acidtogether with soot, cinders, and mechanical impurities from the furnace.

It has been commonly noticed that artical stone as usually hardened by the action ot' carbonic-acid gas is streaked or discolored with spots or blotches, which render the stone less desirable for exposed Worlgand especially for facings and ornamental trimmings. It has also been noticed that in thus hardening imitation Egyptian, Tennessee, and other handsome marblesyin which various mineral coloring-matters are employed, the brilliancy of the sameis impaired. For this reason the carbonization of such articles is commonly omitted. I have discovered that this discoloration is owing. to the presence of sulphureted hydrogen, soot, oinders, and other impurities found in the carbonio-acid gas and carried by it from the generating-chamber to the hardeningcomizing-'ohamber D.

its injurious properties, and this, too, without or interfering inany'm'anner with the operation. V'Iho soot, cinders, and other mechanical impurities are deposited in the water, and the sulphureted hydrogen, which acts upon and impairs thebrilliancy of the mineral coloring-matter offaney marbles, is fully dissolved in and arrested by the water.

In the drawing is shown in elevation'lthe apparatus I use. In it A is the oven, connected by a pipe, a, with the water-seal or puriier (l, whence a pipe, b, leads to the carbong A blower, B, serves to draw the products of combustion and force them through the water.

Inoperation a tire is built in the oven A, the blower is set in. motion, and the stones to be treated are placed in the building D. l The gas is caused to bubble through the water seal or trap C, removing mechanical impurities and cooling the gas, which is then conducted into the chamber D, in which the stone is placed. I The gas, being cold, retards the drying of the stones, and the water mechanically held by them absorbs the carbonio-acid gas, causing it to penetrate the stones to a much greater depth than it would were the gas heated.

y The gas may be prepared by action of an acid on a carbonate, or by calcination, if preferred.

The carbonization is rapidly eiiected and far more thoroughly than has heretofore been possible.

The water used to purify the gas contains, being asaturated solution and cold, nearly its own volume of carbonio acid gas. Except mechanical impurities, which are readily removed by subsidence or filtration, it contains little or nothing else, and may be considered a pure saturated solution of carbonio acid in water. This I use instead of water for dampening the cement, and also use it in the form ota Wash to harden the stone after formation and partial or complete drying. I am fully aware ofthe inventions described andclaimed in the patents o'James Rowland, of D. W. Sprogleand of George Richardson, in which carbonio-acid gas, either alone or mixed with steam or water, and in vvarious l ing artificial stone, the same consisting in pre-V is employed for the purpose of hardening articial stone. I wish, therefore, to be distinctly understood as making no claim to the matters and things therein set forth. I am further aware that it scommon to wash various kinds of gas before using the same,

and am informed that carbonio-acid gas used in bread-making has been washed to relieve it of impurities which might injure the bread. I am not aware, however, that prior to my invention itjhas been known that the blotches and discolorations of artificial stone were the result of impurites of the gas, nor that thesev impurities were of such a character that they could be thoroughly removed by water, and this, too, withoutimpairing the hardening process.

What I claim isl. The method herein described of hardenparing a supply of carbonic-acid gas, substantially in the manner described, conducting said gas through and under the surface of a body of water, whereby all impurities are removed and the gas is cooled, and vfinally conducting said purified and cooled gasinto the hardeningchamber containing the stone, substantially as described.

2. The apparatus for hardening artificial stone herein described, consisting ot' a gasgenerating chamber for carbonio-acid gas, a water-seal for arresting the impurities ot' the gas, and a hardening-compartment wherein the stone is subjected to the action of the puritied gas, substantially as described.

DAVID'G. WEEMS.

Witnesses:

GEO. R. GAITHER, Jr., GEO. A. HEMMICK. 

